Generic rubber-tired rollers are typically employed for ground compaction and in particular for asphalt compaction in road construction. They are self-propelled machines which usually include a machine frame, a drive engine and a chassis driven by the drive engine with a front chassis part and a rear chassis part. Typically, at least one chassis part comprises at least two tires with running surfaces, which are arranged next to one another. The tires are normally made of an elastic material, for example a rubber material. The elastic properties of the tires traveling over the ground result in a kneading or flexing effect, due to which the use of generic rubber-tired rollers results in a particularly effective pore seal at the surface of the layer to be compacted.
Particularly in road construction, it is a standard practice that the rubber-tired rollers travel over the asphalt material to be compacted while the latter is still hot. Due to the increased temperature, the viscosity of the binder portions of the asphalt layer, for example the bitumen, is still low enough, so that a sufficient compaction can be achieved. As the temperature of the asphalt decreases, however, it becomes more viscous and thus harder to compact. It is a known problem in asphalt compaction with rubber-tired rollers that the hot asphalt material adheres to cold tires of the rubber-tired roller due to the property described above. It thus frequently happens, in particular at the beginning of the works when the tires are still significantly colder than the asphalt material, that asphalt material sticks to the rubber tires, which can cause unevenness of the finished asphalt layer. The tires then heat up in the course of the works until the temperature difference between the tires and the asphalt material is so small that the material does no longer stick to the tires.
To counteract the adherence of material to the tires, it is known, on the one hand, to provide strippers at the rubber tires which remove adhering asphalt material mechanically. Moreover, it is known to employ a sprinkler system for the tires which is configured to apply a liquid separating agent, for example a solvent-free water-dilutable separating agent, to the running surfaces of the tires. A control unit for controlling said sprinkler system is typically also provided. By wetting the tires with said separating agent, adherence of the asphalt material can be prevented from the outset. This, however, requires the rubber-tired roller to carry large quantities of the separating agent. Moreover, the separating agent needs to be refilled once the supply carried by the rubber-tired roller has been exhausted. The aim is therefore to apply the separating agent to the running surfaces of the tires as economically as possible and only if it is actually necessary.
In order to minimize the consumption of separating agent in practice, the operator of the rubber-tired roller thus needs to estimate or monitor at which time there is no longer a risk of adherence of the asphalt material to the tires. Once the tires have been heated sufficiently, the sprinkler system can be turned off. If this is done too early, there is a risk that the asphalt layer is damaged by the removal of pieces adhering to the tires. On the other hand, if the operator turns the sprinkler system off too late, this results in an unnecessary consumption of separating agent. To give the operator an indication for controlling the sprinkler system, it is known in the prior art to determine the temperature of the ground. This enables the operator to better estimate how long he has to process the ground until the tires have heated up sufficiently. Even with the measurement of the ground temperature, however, the decision of the operator to turn the sprinkler system off remains very subjective, so that there is still the risk of damage to the asphalt layer on the one hand and unnecessary consumption of separating agent on the other hand.